1. Field of the Invention
The present invention relates to an image reading apparatus, a control method and a computer readable program storage of the apparatus.
2. Description of the Related Art
In late years, a document-sheet conveying device is mounted in an image reading apparatus for reading an image of a document sheet. Therefore, a moving-document-reading method is generally used in which a plurality of document sheets are set at the document-sheet conveying device and the plurality of document sheets are read using a fixed optical system unit by separating and transporting the plurality of document sheets. Also, in the case where a plurality of document sheets are read by using an image reading apparatus without the document-sheet conveying device, a stationary-document-reading method is used in which a plurality of document sheets is set one by one on a document positioning glass plate of the image reading apparatus and the plurality of document sheets are repeatedly read using a optical system.
Such an image reading apparatus usually has a document-sheet-size detection mechanism. For example, when reading is performed using the document-sheet conveying device, a size of the document sheet is determined using a sensor of the document-sheet conveying device, and reading can be performed depending on the size. And then, a copy process can be performed such that a printing apparatus prints data on a sheet of the detected document size.
Also, in late years, development of “electrical paper” having both benefits of a paper and a display has been developed, and it is devised that an electrical paper is used in substitution for paper. Waste of paper can be restrained by using the electrical paper in substitution for paper. In such a background, a method to read both of a paper document-sheet and an electrical paper by using a document-sheet conveying device is devised as a method to read an image shown on the electrical paper by an image reading apparatus as disclosed in Japanese Paten Laid-Open No. 2008-141590.
A size of image data displayed on an electrical paper may not fit into a size of the electrical paper. For example, image data of the A3 size may be reduced to the A4 size and displayed on an electrical paper of the A4 size. Image data of the B5 size may be displayed on the electrical paper of the A4 size.
In the above cases, if an image reading apparatus performs reading of a document-sheet using the document-sheet-size detection mechanism that is conventional art, the detected size of a document sheet will not fit a real size of image data. That is, for example, a printed matter including a useless blank space will be provided if a copy process is performed in such situation because an image of the B5 size is printed on a paper of the A4 size detected by the document-sheet-size detection mechanism.
Thus, if reading of an electrical paper is performed using the document-sheet-size detection mechanism of conventional art, the reading that does not desired by a user might be performed due to mismatch between a size of the document sheet (a size of the electrical paper itself) and a size of displayed image data. Alternatively, a copy process that is not desired by a user might be performed.
The present invention is intended to solve such an issue. That is, the present invention is directed to preventing the reading undesired by the user when the image reading apparatus reads the electrical paper.